Mwalimu alisema nitamke neno hilo polepole.

It breaks down like this:

• ni- = I
• -tamk- = the verb root from kutamka = to pronounce / to say
• -e = the subjunctive ending

So nitamke means something like that I pronounce or I should pronounce.

Because the ta here is part of the verb root -tamka, not the future marker.

Compare:

• nitamke = I should pronounce / that I pronounce
• nitatamka = I will pronounce

That second form has the real future marker -ta- plus the root -tamka.

There is no separate word for should here. Swahili often uses the subjunctive to express ideas like:

• should
• to after commands or instructions
• let / may

So alisema nitamke is literally close to he/she said that I pronounce, but naturally it means the teacher said I should pronounce.

Because this is the subjunctive form.

The basic verb is:

• kutamka = to pronounce

But after a reported instruction, command, request, or wish, Swahili often changes the final vowel to -e:

• nitamke
• utamke
• atamke

So the -e shows that this is not a plain statement, but an instruction or intended action.

Because kwamba is often optional.

You can say:

• Mwalimu alisema nitamke neno hilo polepole.
• Mwalimu alisema kwamba nitamke neno hilo polepole.

Both are grammatical. The version without kwamba is very normal and natural.

It can mean either, depending on context.

• With a word, it often means pronounce
• In other contexts, it can mean say, utter, or declare

Here, because the object is neno hilo and the adverb is polepole, pronounce is the most natural translation.

Because in Swahili, demonstratives normally come after the noun.

So:

• neno hilo = that word
• kitabu hiki = this book
• mtu yule = that person

English puts this/that before the noun, but Swahili usually puts the demonstrative after it.

Because neno belongs to noun class 5, and the demonstrative has to agree with that class.

For class 5 singular, the common demonstratives are:

• hili = this
• hilo = that
• lile = that over there / that more distant one

So neno hilo is the correct agreement.
You cannot use hiyo here, because hiyo belongs to a different noun class.

Polepole means slowly.

It looks repeated because many Swahili adverbs and expressive words have this kind of doubled form. In this case, polepole is the normal word for slowly.

Related forms:

• pole can mean sorry, gently, or take it easy
• polepole specifically means slowly / little by little

So this is not an unusual repetition in the sentence; it is just the standard adverb.

Yes. That would also be natural.

The difference is:

• alisema = said
• aliniambia = told me / said to me

So:

• Mwalimu alisema nitamke... = The teacher said I should pronounce...
• Mwalimu aliniambia nitamke... = The teacher told me to pronounce...

The second version makes it more explicit that the teacher was speaking to me.

This is indirect speech.

A direct version might be:

• Mwalimu alisema: Tamka neno hilo polepole.

That means the teacher directly said Tamka... to someone.

In the indirect version, the command is reported from the speaker’s point of view, so it becomes nitamke = that I should pronounce.

Because Swahili does not use articles like English a and the.

So mwalimu can mean:

• a teacher
• the teacher

The context tells you which one is meant.

In this sentence, English naturally uses the teacher, but Swahili does not need a separate word for that.